Analysis of Fall Transition Season (Sept-Early Dec) Why has the weather been so violent?

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "Analysis of Fall Transition Season (Sept-Early Dec) Why has the weather been so violent?"

Transcription

1 WEATHER TOPICS Analysis of Fall Transition Season (Sept-Early Dec) 2009 Why has the weather been so violent? As can be seen by the following forecast map, the Fall Transition and early Winter Season of 2009 has been particularly heavy in the North Pacific, with several very deep low pressure systems, long fetches of over 1,000nm with very strong winds, and extremely wide areas of over 6m seas/swells. Reasons for such violent weather are related to several features, including the El Niño phenomenon, sea surface temperatures, global circulation patterns and slightly higher than average tropical cyclone activity in the Northwest Pacific, many of which recurved into the subtropics, bringing warm, moist air which helps fuel explosive development of low pressure systems. For a detailed scientific analysis of the mechanisms involved, please see the following pages.

2 Introduction The Fall Transition Season of 2009 has been particularly heavy in the North Pacific the period September through early December has boasted ten low pressure systems deeper that 970mb, four of which showed central pressures less than 955mb (Figure 1). The presence of a moderate El Niño over the past several months (Figure 2), and its effect on Tropical Storm development, sea surface temperatures and global circulation patterns can be traced as the reason for this particularly heavy weather. El Niño El Niño is part of the climate phenomenon called ENSO El Niño/ Southern Oscillation - which is a periodic change in the atmosphere and ocean of the tropical Pacific. It is defined in the atmosphere by the sign of the pressure difference between Tahiti and Darwin, Australia, and in the ocean by warming or cooling of surface waters of the tropical central and eastern Pacific Ocean. The warm phase of ENSO is known as El Niño, and the cold phase of ENSO is known as La Niña (Figure 3). ENSO events (warm or cool) do not occur with a specific period, and tend to occur every three to eight years. The effects of ENSO are felt globally, but are felt most acutely in the Pacific Ocean, as sea surface temperature anomalies associated with ENSO can affect the circulation patterns of the basin. During El Niño events, the atmospheric pattern is characterized by an eastward extension of the East Asian jest stream from the International Date Line to the southwestern United States, and shifting of that jet stream further south through the mid-latitudes. This results in an amplified main low track and enhanced Aleutian low (Figure 4), meaning that lows within the main low track tend to be stronger, and track further south through the basin. Tropical Storms and Sea Surface Temperatures The transition season of 2009 has seen 15 tropical systems (tropical storm strength and higher), which is near the average of about 13 storms of TS strength or higher for the period September-November (Table 1). Recent research by the Weathernews Voyage Planning team indicates that El Niño typically does not have an effect on the total number of tropical systems average number of storms remains consistent between El Niño, Neutral and La Niña years. However, there are on average 2 more typhoons per year in El Niño years than in neutral or La Niña years. His research shows that tropical cyclones form farther south and east during El Niño event than in neutral or La Niña years (Figure 5). Forming farther south, these cyclones tend to track westward in warmer waters for longer periods of time, allowing tropical depressions to reach tropical storm strength and typhoon strength farther south and east in the basin. Per Lance s research, tropical cyclones tend reach higher maximum wind intensities during El Niño

3 years (on average knots higher than in neutral or La Niña years), and they tend to recurve slightly more often than in ENSO Neutral years and much more often than during La Niña years. The Fall transition season of 2009 (September early December) has seen 19 tropical systems develop, 15 of which were tropical storm strength or higher. Of those 15 systems, 7 recurved through the western ocean into the mid-latitudes of the West or Central Pacific. Four of those recurving systems (Choi-wan, Melor, Lupit and Nida) were significant Typhoons, with maximum wind speeds of 105 kt and higher recorded during their lifetimes. The seven recurving tropical systems (as well as several tropical depressions that also recurved) during this period brought rich tropical moisture in the mid-latitudes, which helped prime the atmosphere for more violent weather during this transition season in two ways. Firstly, recurving tropical systems bring warm, humid air to the mid latitudes. When that warm, humid air converges with cold air associated with mid-latitude systems, the warm, humid air can serve as fuel for the mid-latitude systems by providing additional latent heat energy. This allows the mid-latitude storms to deepen further, sometimes very quickly, resulting in intense storms with very heavy associated conditions. Such was the case with Typhoons Choi-wan (in Mid-September), Lupit (in late October) and Nida (in early December), each of which deepened to lows with central pressure of 967mb or lower after extratropical transition or combining with mid-latitude low. Secondly, strong recurving tropical systems (as in the case with the four systems mentioned above) typically have strong southerly winds along the eastern side of the system. These strong winds can serve to push warm surface waters northward from the tropics into the mid-latitudes. Figure 6 shows a positive sea surface temperature (SST) anomaly was present across much of the West Pacific, west of the Dateline for the period September 1- December 7. This figure shows a significantly positive anomaly between 160E-170E, 35N-40N. Positive sea surface temperature anomalies were also present east of the dateline, south of 40N. The strong anomaly in the Western Pacific can be attributed to strong recurving tropical systems pushing warm SSTs north into the mid-latitudes, effectively warming the average SST in the West Pacific by almost 2.5C in some areas. The presence of this pool of warm water served as additional fuel for developing lows in the Western Pacific. The main cyclogenesis area of the Pacific basin is off the coast of Japan, associated with the Kuroshio current core. With warmer water present over a much larger area than normal, lows that developed off the coast of Japan stayed over these warmer waters for longer, allowing them to gain more energy than they would normally. When those lows converged with cold air as they tracked northeastward into the Bering Sea or Gulf of Alaska, this additional energy allowed lows to deepen further and more quickly than if a typical sea surface temperature distribution was present across the basin.

4 The PNA and El Niño The Pacific North American (PNA) Index is a climate index that describes one of the most prominent modes of low-frequency variability in the Northern Hemisphere extratropics. The positive phase of the PNA is characterized by a stronger than normal Aleutian low, and a stronger high pressure system over the western US (Figure 7). The negative phase of the PNA is characterized by weaker than normal lows across the Aleutians/Central Pacific, but a stronger trough across the western United States. The PNA is a natural mode of climate variability, but it tends to very strongly with ENSO events the positive phase of the PNA is strongly correlated to El Niño events, while the negative phase is strongly correlated to La Niña events. (Climate Prediction Center: The period of September-November 2009 showed an average PNA value of The average sea level pressure anomaly for the period 1 September 7 December (Figure 8) is in line with the characteristics of a positive PNA, with a deep anomaly over the Aleutian Islands and Gulf of Alaska. Eight of the ten storms that were observed to have central pressures of less than 970mb occurred when the PNA Index was in a positive phase (Figure 9), meaning that the Aleutian Low, and the main low track was enhanced. Conclusion The presence of several recurving tropical systems over the western Pacific affected the weather pattern during the transition season in two ways. Firstly, warm, humid tropical air was carried into the mid-latitudes as these systems tracked northeastward and merged with the main low track. Secondly, several strong recurving typhoons served to push warmer tropical waters northward into the mid-latitudes, causing a warm SST anomaly to develop across the western Pacific. This allowed low pressure systems that developed off the coast of Japan to remain over warmer waters for longer; when those lows then interacted with cold air at higher latitudes, the resulting dynamics allowed lows to deepen further, and often more rapidly, than typically is expected. Similarly, the effects of El Niño on the general weather pattern of the North Pacific, and El Niño s interaction with the Pacific/North American pattern resulted in an enhanced Aleutian low pressure system across the central Pacific and Gulf of Alaska, resulting in a more active main low track across the basin. The enhanced main low track served to allow stronger low pressure systems to develop (in concert with the observed SST anomaly), which caused the several violent storms that were observed over the course of this transition season.

5 Figure 1. Ninety-day average wave heights (m) and storm tracks for the period 11 September 09 December. Courtesy Climate Prediction Center :

6 Figure 2. Time series of area averaged sea surface temperature anomalies in the Niño regions [Niño-1+2 (0-10S, 90W-80W), Niño-3 (5N-5S, 150W-90W), Niño-3.4 (5N-5S, 170W-120W), Niño-4 (5N-5S, 150W-160E)]. SST anomalies are departures from the base period weekly means. (Xue et. al., 2003, J. Climate, 16, ). Graphics courtesy Climate Prediction Center.

7 Figure 3. Typical Sea surface temperature anomaly distributions associated the warm (El Niño) phase and cool (La Niña) phase of the ENSO Cycle. Graphic courtesy National Oceanic and Atmospheric Administration.

8 Figure 4. Typical winter weather patters during El Niño and La Niña events. Courtesy Climate Prediction Center (

9 Month 2009 Average September October 5 (plus 1 TD) 4.7 November 3 (plus 2 TDs) 2.9 December** 0 (Plus 1 TD) 1.6 Table 1. Number of tropical systems of tropical storm strength and higher in the West Pacific. This list does not include Tropical Depressions (TD). However, there have been a total of 4 TDs in the NW Pacific in Oct., Nov., and Dec. 2009, many of which have brought tropical moisture into the mid-latitudes.** As of Dec-07, 2009 Figure 5. Mean position for tropical depression formation across the western Pacific for Strong La Niña, La Niña, ENSO Neutral, El Niño and strong El Niño events. Chart produced by the WNI-Voyage Planning team.

10 Figure 6. Average sea surface temperature anomaly (degrees C) for the period September 1 December 7, as compared to climatogical mean From NCAR/NCEP global Reanalysis Data provided by Earth System Research Laboratory. Figure 7. Empirical Orthogonal Function loading pattern for sea level pressure anomalies associated with the positive phase of the Pacific/North American Index. Courtesy Joint Institute for the study of Atmosphere and Ocean.

11 Figure 8. Composite mean Sea Level Pressure anomaly for the period September 1 December 7, as compared to climatogical mean From NCAR/NCEP global Reanalysis Data provided by Earth System Research Laboratory. Figure 9. Observed daily PNA Index value. Vertical lines indicate the approximate date of storms that were observed to have central pressures of less than 970mb. Pink Lines indicate Positive PNA value at the time of observation and green lines indicate Negative PNA value at the time of observation. PNA index figure courtesy Climate Prediction Center (

Percentage of normal rainfall for August 2017 Departure from average air temperature for August 2017

Percentage of normal rainfall for August 2017 Departure from average air temperature for August 2017 New Zealand Climate Update No 219, August 2017 Current climate August 2017 Overall, mean sea level pressure was lower than normal over and to the west of New Zealand during August while higher than normal

More information

New Zealand Climate Update No 223, January 2018 Current climate December 2017

New Zealand Climate Update No 223, January 2018 Current climate December 2017 New Zealand Climate Update No 223, January 2018 Current climate December 2017 December 2017 was characterised by higher than normal sea level pressure over New Zealand and the surrounding seas. This pressure

More information

ALASKA REGION CLIMATE FORECAST BRIEFING. October 27, 2017 Rick Thoman National Weather Service Alaska Region

ALASKA REGION CLIMATE FORECAST BRIEFING. October 27, 2017 Rick Thoman National Weather Service Alaska Region ALASKA REGION CLIMATE FORECAST BRIEFING October 27, 2017 Rick Thoman National Weather Service Alaska Region Today Feature of the month: West Pacific Typhoons Climate Forecast Basics Climate System Review

More information

4/29/2011. Mid-latitude cyclones form along a

4/29/2011. Mid-latitude cyclones form along a Chapter 10: Cyclones: East of the Rocky Mountain Extratropical Cyclones Environment prior to the development of the Cyclone Initial Development of the Extratropical Cyclone Early Weather Along the Fronts

More information

Global Climate Patterns and Their Impacts on North American Weather

Global Climate Patterns and Their Impacts on North American Weather Global Climate Patterns and Their Impacts on North American Weather By Julie Malmberg and Jessica Lowrey, Western Water Assessment Introduction This article provides a broad overview of various climate

More information

Weather and Climate Summary and Forecast March 2018 Report

Weather and Climate Summary and Forecast March 2018 Report Weather and Climate Summary and Forecast March 2018 Report Gregory V. Jones Linfield College March 7, 2018 Summary: The ridge pattern that brought drier and warmer conditions from December through most

More information

Satellites, Weather and Climate Module??: Polar Vortex

Satellites, Weather and Climate Module??: Polar Vortex Satellites, Weather and Climate Module??: Polar Vortex SWAC Jan 2014 AKA Circumpolar Vortex Science or Hype? Will there be one this year? Today s objectives Pre and Post exams What is the Polar Vortex

More information

Early May Cut-off low and Mid-Atlantic rains

Early May Cut-off low and Mid-Atlantic rains Abstract: Early May Cut-off low and Mid-Atlantic rains By Richard H. Grumm National Weather Service State College, PA A deep 500 hpa cutoff developed in the southern Plains on 3 May 2013. It produced a

More information

New Zealand Climate Update No 226, April 2018 Current climate March 2018

New Zealand Climate Update No 226, April 2018 Current climate March 2018 New Zealand Climate Update No 226, April 2018 Current climate March 2018 March 2018 was characterised by significantly higher pressure than normal to the east of New Zealand. This pressure pattern, in

More information

UPDATE OF REGIONAL WEATHER AND SMOKE HAZE (February 2018)

UPDATE OF REGIONAL WEATHER AND SMOKE HAZE (February 2018) UPDATE OF REGIONAL WEATHER AND SMOKE HAZE (February 2018) 1. Review of Regional Weather Conditions for January 2018 1.1 The prevailing Northeast monsoon conditions over Southeast Asia strengthened in January

More information

National Wildland Significant Fire Potential Outlook

National Wildland Significant Fire Potential Outlook National Wildland Significant Fire Potential Outlook National Interagency Fire Center Predictive Services Issued: September, 2007 Wildland Fire Outlook September through December 2007 Significant fire

More information

Percentage of normal rainfall for April 2018 Departure from average air temperature for April 2018

Percentage of normal rainfall for April 2018 Departure from average air temperature for April 2018 New Zealand Climate Update No 227, May 2018 Current climate April 2018 Overall, April 2018 was characterised by lower pressure than normal over and to the southeast of New Zealand. Unlike the first three

More information

KUALA LUMPUR MONSOON ACTIVITY CENT

KUALA LUMPUR MONSOON ACTIVITY CENT T KUALA LUMPUR MONSOON ACTIVITY CENT 2 ALAYSIAN METEOROLOGICAL http://www.met.gov.my DEPARTMENT MINISTRY OF SCIENCE. TECHNOLOGY AND INNOVATIO Introduction Atmospheric and oceanic conditions over the tropical

More information

Weather and Climate Summary and Forecast December 2017 Report

Weather and Climate Summary and Forecast December 2017 Report Weather and Climate Summary and Forecast December 2017 Report Gregory V. Jones Linfield College December 5, 2017 Summary: November was relatively cool and wet from central California throughout most of

More information

Winter Forecast. Allan Huffman RaleighWx

Winter Forecast. Allan Huffman RaleighWx Winter 2014-15 Forecast Allan Huffman RaleighWx Winter 2014-15 Combination of weak/moderate El Nino/+PDO/-QBO and well above average snow cover and snow cover increase this Fall in Siberia point to a winter

More information

Weather and Climate Summary and Forecast January 2018 Report

Weather and Climate Summary and Forecast January 2018 Report Weather and Climate Summary and Forecast January 2018 Report Gregory V. Jones Linfield College January 5, 2018 Summary: A persistent ridge of high pressure over the west in December produced strong inversions

More information

South & South East Asian Region:

South & South East Asian Region: Issued: 15 th December 2017 Valid Period: January June 2018 South & South East Asian Region: Indonesia Tobacco Regions 1 A] Current conditions: 1] El Niño-Southern Oscillation (ENSO) ENSO Alert System

More information

Please be ready for today by:

Please be ready for today by: Please be ready for today by: 1. HW out for a stamp 2. Paper and pencil/pen for notes 3. Be ready to discuss what you know about El Nino after you view the video clip What is El Nino? El Nino Basics El

More information

ENSO UPDATE By Joseph D Aleo, CCM

ENSO UPDATE By Joseph D Aleo, CCM ENSO UPDATE By Joseph D Aleo, CCM El Nino is still hanging on but likely not for very long. Warmer than normal water can still be seen along the equator in the tropical Pacific. It is even warmer in the

More information

Weather and Climate Summary and Forecast April 2018 Report

Weather and Climate Summary and Forecast April 2018 Report Weather and Climate Summary and Forecast April 2018 Report Gregory V. Jones Linfield College April 4, 2018 Summary: A near Miracle March played out bringing cooler and wetter conditions to the majority

More information

Weather and Climate Summary and Forecast October 2017 Report

Weather and Climate Summary and Forecast October 2017 Report Weather and Climate Summary and Forecast October 2017 Report Gregory V. Jones Linfield College October 4, 2017 Summary: Typical variability in September temperatures with the onset of fall conditions evident

More information

El Niño / Southern Oscillation

El Niño / Southern Oscillation El Niño / Southern Oscillation Student Packet 2 Use contents of this packet as you feel appropriate. You are free to copy and use any of the material in this lesson plan. Packet Contents Introduction on

More information

ALASKA REGION CLIMATE OUTLOOK BRIEFING. December 22, 2017 Rick Thoman National Weather Service Alaska Region

ALASKA REGION CLIMATE OUTLOOK BRIEFING. December 22, 2017 Rick Thoman National Weather Service Alaska Region ALASKA REGION CLIMATE OUTLOOK BRIEFING December 22, 2017 Rick Thoman National Weather Service Alaska Region Today s Outline Feature of the month: Autumn sea ice near Alaska Climate Forecast Basics Climate

More information

Fire Weather Drivers, Seasonal Outlook and Climate Change. Steven McGibbony, Severe Weather Manager Victoria Region Friday 9 October 2015

Fire Weather Drivers, Seasonal Outlook and Climate Change. Steven McGibbony, Severe Weather Manager Victoria Region Friday 9 October 2015 Fire Weather Drivers, Seasonal Outlook and Climate Change Steven McGibbony, Severe Weather Manager Victoria Region Friday 9 October 2015 Outline Weather and Fire Risk Environmental conditions leading to

More information

ESCI 241 Meteorology Lesson 19 Tropical Cyclones Dr. DeCaria

ESCI 241 Meteorology Lesson 19 Tropical Cyclones Dr. DeCaria ESCI 241 Meteorology Lesson 19 Tropical Cyclones Dr. DeCaria READING: Chapter 16 GENERAL A tropical cyclone is a large, low-pressure system that forms over the tropical oceans. Tropical cyclones are classified

More information

Winds and Global Circulation

Winds and Global Circulation Winds and Global Circulation Atmospheric Pressure Winds Global Wind and Pressure Patterns Oceans and Ocean Currents El Nino How is Energy Transported to its escape zones? Both atmospheric and ocean transport

More information

California 120 Day Precipitation Outlook Issued Tom Dunklee Global Climate Center

California 120 Day Precipitation Outlook Issued Tom Dunklee Global Climate Center California 120 Day Precipitation Outlook Issued 11-01-2008 Tom Dunklee Global Climate Center This is my second updated outlook for precipitation patterns and amounts for the next 4 s of the current rainy

More information

b. The boundary between two different air masses is called a.

b. The boundary between two different air masses is called a. NAME Earth Science Weather WebQuest Part 1. Air Masses 1. Find out what an air mass is. http://okfirst.mesonet.org/train/meteorology/airmasses.html a. What is an air mass? An air mass is b. The boundary

More information

Weather and Climate Summary and Forecast Winter

Weather and Climate Summary and Forecast Winter Weather and Climate Summary and Forecast Winter 2016-17 Gregory V. Jones Southern Oregon University December 5, 2016 Well after an October that felt more like November, we just finished a November that

More information

Hurricanes Part I Structure and Climatology by Professor Steven Businger. Hurricane Katrina

Hurricanes Part I Structure and Climatology by Professor Steven Businger. Hurricane Katrina Hurricanes Part I Structure and Climatology by Professor Steven Businger Hurricane Katrina Hurricanes Part I Structure and Climatology by Professor Steven Businger What is a hurricane? What is the structure

More information

Weather and Climate Summary and Forecast Summer 2017

Weather and Climate Summary and Forecast Summer 2017 Weather and Climate Summary and Forecast Summer 2017 Gregory V. Jones Southern Oregon University August 4, 2017 July largely held true to forecast, although it ended with the start of one of the most extreme

More information

Ocean cycles and climate ENSO, PDO, AMO, AO

Ocean cycles and climate ENSO, PDO, AMO, AO Ocean cycles and climate ENSO, PDO, AMO, AO 3 2.5 2 enso-index 1.5 1 0.5 0-0.5-1 enso 3.4 -index - 1996 to 1999-1.5 1996 1997 1998 1999 Bob Tisdale Bob Tisdale Bob Tisdale ENSO mechanisms animation http://esminfo.prenhall.com/science/geoanimations/animations/26_ninonina.html

More information

Unseasonable weather conditions in Japan in August 2014

Unseasonable weather conditions in Japan in August 2014 Unseasonable weather conditions in Japan in August 2014 Summary of analysis by the TCC Advisory Panel on Extreme Climatic Events In an extraordinary session held at the Japan Meteorological Agency on 3

More information

At the Midpoint of the 2008

At the Midpoint of the 2008 At the Midpoint of the 2008 Atlantic Hurricane Season Editor s note: It has been an anxious couple of weeks for those with financial interests in either on- or offshore assets in the Gulf of Mexico and

More information

New Zealand Climate Update No 222, November 2017 Current climate November 2017

New Zealand Climate Update No 222, November 2017 Current climate November 2017 New Zealand Climate Update No 222, November 2017 Current climate November 2017 November 2017 was characterised by higher than normal sea level pressure over New Zealand and the surrounding seas, particularly

More information

Weather Outlook: 2015 Growing Season

Weather Outlook: 2015 Growing Season Weather Outlook: 2015 Growing Season Leon F. Osborne Chester Fritz Distinguished Professor Regional Weather Information Center University of North Dakota Grand Forks, North Dakota Why Should We Be Concerned?

More information

ENSO, AO, and climate in Japan. 15 November 2016 Yoshinori Oikawa, Tokyo Climate Center, Japan Meteorological Agency

ENSO, AO, and climate in Japan. 15 November 2016 Yoshinori Oikawa, Tokyo Climate Center, Japan Meteorological Agency ENSO, AO, and climate in Japan 15 November 2016 Yoshinori Oikawa, Tokyo Climate Center, Japan Meteorological Agency Aims of this lecture At the end of the yesterday s lecture, Hare-run said, - In the exercise

More information

ENSO Cycle: Recent Evolution, Current Status and Predictions. Update prepared by Climate Prediction Center / NCEP 15 July 2013

ENSO Cycle: Recent Evolution, Current Status and Predictions. Update prepared by Climate Prediction Center / NCEP 15 July 2013 ENSO Cycle: Recent Evolution, Current Status and Predictions Update prepared by Climate Prediction Center / NCEP 15 July 2013 Outline Overview Recent Evolution and Current Conditions Oceanic Niño Index

More information

An upper to mid level circulation (Low) in the NW Caribbean is

An upper to mid level circulation (Low) in the NW Caribbean is WEEKLY WEATHER OUTLOOK BELIZE, CENTRAL AMERICA PERIOD: Monday-Monday, Oct. 1 October 8, 2012 DATE ISSUED: Monday, Oct 1, 2012 6:00 am RFrutos EcoSolutions & Services SYNOPSIS: An upper to mid level circulation

More information

Charles Jones ICESS University of California, Santa Barbara CA Outline

Charles Jones ICESS University of California, Santa Barbara CA Outline The Influence of Tropical Variations on Wintertime Precipitation in California: Pineapple express, Extreme rainfall Events and Long-range Statistical Forecasts Charles Jones ICESS University of California,

More information

Seasonal Climate Watch November 2017 to March 2018

Seasonal Climate Watch November 2017 to March 2018 Seasonal Climate Watch November 2017 to March 2018 Date issued: Oct 26, 2017 1. Overview The El Niño Southern Oscillation (ENSO) continues to develop towards a La Niña state, and is expected to be in at

More information

Weather and Climate Summary and Forecast November 2017 Report

Weather and Climate Summary and Forecast November 2017 Report Weather and Climate Summary and Forecast November 2017 Report Gregory V. Jones Linfield College November 7, 2017 Summary: October was relatively cool and wet north, while warm and very dry south. Dry conditions

More information

Weather and Climate Summary and Forecast Winter

Weather and Climate Summary and Forecast Winter Weather and Climate Summary and Forecast Winter 2016-17 Gregory V. Jones Southern Oregon University February 7, 2017 What a difference from last year at this time. Temperatures in January and February

More information

The North Atlantic Oscillation: Climatic Significance and Environmental Impact

The North Atlantic Oscillation: Climatic Significance and Environmental Impact 1 The North Atlantic Oscillation: Climatic Significance and Environmental Impact James W. Hurrell National Center for Atmospheric Research Climate and Global Dynamics Division, Climate Analysis Section

More information

ALASKA REGION CLIMATE OUTLOOK BRIEFING. November 17, 2017 Rick Thoman National Weather Service Alaska Region

ALASKA REGION CLIMATE OUTLOOK BRIEFING. November 17, 2017 Rick Thoman National Weather Service Alaska Region ALASKA REGION CLIMATE OUTLOOK BRIEFING November 17, 2017 Rick Thoman National Weather Service Alaska Region Today Feature of the month: More climate models! Climate Forecast Basics Climate System Review

More information

2013 Summer Weather Outlook. Temperatures, Precipitation, Drought, Hurricanes and why we care

2013 Summer Weather Outlook. Temperatures, Precipitation, Drought, Hurricanes and why we care 2013 Summer Weather Outlook Temperatures, Precipitation, Drought, Hurricanes and why we care Role of the ERCOT Meteorologist Forecasts Develop temperature input for hourly load forecasts (next day, days

More information

South & South East Asian Region:

South & South East Asian Region: Issued: 10 th November 2017 Valid Period: December 2017 May 2018 South & South East Asian Region: Indonesia Tobacco Regions 1 A] Current conditions: 1] El Niño-Southern Oscillation (ENSO) ENSO Alert System

More information

ENSO Cycle: Recent Evolution, Current Status and Predictions. Update prepared by Climate Prediction Center / NCEP 5 August 2013

ENSO Cycle: Recent Evolution, Current Status and Predictions. Update prepared by Climate Prediction Center / NCEP 5 August 2013 ENSO Cycle: Recent Evolution, Current Status and Predictions Update prepared by Climate Prediction Center / NCEP 5 August 2013 Outline Overview Recent Evolution and Current Conditions Oceanic Niño Index

More information

Introduction of Seasonal Forecast Guidance. TCC Training Seminar on Seasonal Prediction Products November 2013

Introduction of Seasonal Forecast Guidance. TCC Training Seminar on Seasonal Prediction Products November 2013 Introduction of Seasonal Forecast Guidance TCC Training Seminar on Seasonal Prediction Products 11-15 November 2013 1 Outline 1. Introduction 2. Regression method Single/Multi regression model Selection

More information

Air Masses of North America cp and ca air masses Air mass characterized by very cold and dry conditions

Air Masses of North America cp and ca air masses Air mass characterized by very cold and dry conditions Chapter 8: Air Masses, Fronts, and Middle-Latitude Cyclones Air masses Fronts Middle-latitude cyclones Air Masses Air mass an extremely large body of air whose properties of temperature and humidity are

More information

THE ATMOSPHERE IN MOTION

THE ATMOSPHERE IN MOTION Funding provided by NOAA Sectoral Applications Research Project THE ATMOSPHERE IN MOTION Basic Climatology Oklahoma Climatological Survey Factor 1: Our Energy Source Hi, I m the Sun! I provide 99.9999+

More information

Weather and Climate Summary and Forecast Summer 2016

Weather and Climate Summary and Forecast Summer 2016 Weather and Climate Summary and Forecast Summer 2016 Gregory V. Jones Southern Oregon University August 5, 2016 The month of July saw the continued flip, flop of the western US temperatures. It was warm

More information

Seasonal Climate Watch January to May 2016

Seasonal Climate Watch January to May 2016 Seasonal Climate Watch January to May 2016 Date: Dec 17, 2015 1. Advisory Most models are showing the continuation of a strong El-Niño episode towards the latesummer season with the expectation to start

More information

Outlook 2008 Atlantic Hurricane Season. Kevin Lipton, Ingrid Amberger National Weather Service Albany, New York

Outlook 2008 Atlantic Hurricane Season. Kevin Lipton, Ingrid Amberger National Weather Service Albany, New York Outlook 2008 Atlantic Hurricane Season Kevin Lipton, Ingrid Amberger National Weather Service Albany, New York Summary 2007 Hurricane Season Two hurricanes made landfall in the Atlantic Basin at category-5

More information

Bell Work. REVIEW: Our Planet Earth Page 29 Document A & B Questions

Bell Work. REVIEW: Our Planet Earth Page 29 Document A & B Questions 9.12.16 Bell Work REVIEW: Our Planet Earth Page 29 Document A & B Questions Intro to Climate & Weather https://www.youtube.com/watch?v=vhgyoa70q7y Weather vs. Climate Video Climate & Weather 3.1 Weather

More information

Waves and Weather. 1. Where do waves come from? 2. What storms produce good surfing waves? 3. Where do these storms frequently form?

Waves and Weather. 1. Where do waves come from? 2. What storms produce good surfing waves? 3. Where do these storms frequently form? Waves and Weather 1. Where do waves come from? 2. What storms produce good surfing waves? 3. Where do these storms frequently form? 4. Where are the good areas for receiving swells? Where do waves come

More information

THEME: Seasonal forecast: Climate Service for better management of risks and opportunities

THEME: Seasonal forecast: Climate Service for better management of risks and opportunities CENTRE AFRICAIN POUR LES APPLICATIONS DE LA METEOROLOGIE AU DEVELOPPEMENT AFRICAN CENTRE OF METEOROLOGICAL APPLICATIONS FOR DEVELOPMENT Institution Africaine parrainée par la CEA et l OMM African Institution

More information

2015: A YEAR IN REVIEW F.S. ANSLOW

2015: A YEAR IN REVIEW F.S. ANSLOW 2015: A YEAR IN REVIEW F.S. ANSLOW 1 INTRODUCTION Recently, three of the major centres for global climate monitoring determined with high confidence that 2015 was the warmest year on record, globally.

More information

ENSO Cycle: Recent Evolution, Current Status and Predictions. Update prepared by Climate Prediction Center / NCEP July 26, 2004

ENSO Cycle: Recent Evolution, Current Status and Predictions. Update prepared by Climate Prediction Center / NCEP July 26, 2004 ENSO Cycle: Recent Evolution, Current Status and Predictions Update prepared by Climate Prediction Center / NCEP July 26, 2004 Outline Overview Recent Evolution and Current Conditions Oceanic NiZo Index

More information

Verification Of January HDD Forecasts

Verification Of January HDD Forecasts Verification Of January HDD Forecasts W2020 / Average HDD stands for Heating Degree Day. A Heating Degree Day is zero if the average temperature is 65 degrees. An HDD of -30 would mean an average temperature

More information

Quiz 2 Review Questions

Quiz 2 Review Questions Quiz 2 Review Questions Chapter 7 Lectures: Winds and Global Winds and Global Winds cont 1) What is the thermal circulation (thermal wind) and how does it form? When we have this type of circulation, how

More information

ARUBA CLIMATOLOGICAL SUMMARY 2017 PRECIPITATION

ARUBA CLIMATOLOGICAL SUMMARY 2017 PRECIPITATION ARUBA CLIMATOLOGICAL SUMMARY 2017 PRECIPITATION The total amount of rainfall recorded at Reina Beatrix International Airport for the year 2017 was 391.0 mm. This is 17.1 % below normal ( Figure 1 ). During

More information

2016 Hurricane Season Preview

2016 Hurricane Season Preview 2016 Hurricane Season Preview Eric Uhlhorn, Ph.D. 1 2 Recap of 2015 Hurricane Season - El Niño played a significant role in activity - Atlantic activity was slightly below normal 11 named storms, 4 hurricanes,

More information

Comments by William M. Gray (Colorado State University) on the recently published paper in Science by Webster, et al

Comments by William M. Gray (Colorado State University) on the recently published paper in Science by Webster, et al Comments by William M. Gray (Colorado State University) on the recently published paper in Science by Webster, et al., titled Changes in tropical cyclone number, duration, and intensity in a warming environment

More information

July Forecast Update for Atlantic Hurricane Activity in 2017

July Forecast Update for Atlantic Hurricane Activity in 2017 July Forecast Update for Atlantic Hurricane Activity in 2017 Issued: 4 th July 2017 by Professor Mark Saunders and Dr Adam Lea Dept. of Space and Climate Physics, UCL (University College London), UK Forecast

More information

Weather Elements (air masses, fronts & storms)

Weather Elements (air masses, fronts & storms) Weather Elements (air masses, fronts & storms) S6E4. Obtain, evaluate and communicate information about how the sun, land, and water affect climate and weather. A. Analyze and interpret data to compare

More information

June 1989 T. Nitta and S. Yamada 375. Recent Warming of Tropical Sea Surface Temperature and Its. Relationship to the Northern Hemisphere Circulation

June 1989 T. Nitta and S. Yamada 375. Recent Warming of Tropical Sea Surface Temperature and Its. Relationship to the Northern Hemisphere Circulation June 1989 T. Nitta and S. Yamada 375 Recent Warming of Tropical Sea Surface Temperature and Its Relationship to the Northern Hemisphere Circulation By Tsuyoshi Nitta and Shingo Yamada Long-Range Forecast

More information

Monitoring and Prediction of Climate Extremes

Monitoring and Prediction of Climate Extremes Monitoring and Prediction of Climate Extremes Stephen Baxter Meteorologist, Climate Prediction Center NOAA/NWS/NCEP Deicing and Stormwater Management Conference ACI-NA/A4A Arlington, VA May 19, 2017 What

More information

Mozambique. General Climate. UNDP Climate Change Country Profiles. C. McSweeney 1, M. New 1,2 and G. Lizcano 1

Mozambique. General Climate. UNDP Climate Change Country Profiles. C. McSweeney 1, M. New 1,2 and G. Lizcano 1 UNDP Climate Change Country Profiles Mozambique C. McSweeney 1, M. New 1,2 and G. Lizcano 1 1. School of Geography and Environment, University of Oxford. 2.Tyndall Centre for Climate Change Research http://country-profiles.geog.ox.ac.uk

More information

1 What Is Climate? TAKE A LOOK 2. Explain Why do areas near the equator tend to have high temperatures?

1 What Is Climate? TAKE A LOOK 2. Explain Why do areas near the equator tend to have high temperatures? CHAPTER 17 1 What Is Climate? SECTION Climate BEFORE YOU READ After you read this section, you should be able to answer these questions: What is climate? What factors affect climate? How do climates differ

More information

Air Masses, Fronts, Storm Systems, and the Jet Stream

Air Masses, Fronts, Storm Systems, and the Jet Stream Air Masses, Fronts, Storm Systems, and the Jet Stream Air Masses When a large bubble of air remains over a specific area of Earth long enough to take on the temperature and humidity characteristics of

More information

The U. S. Winter Outlook

The U. S. Winter Outlook The 2017-2018 U. S. Winter Outlook Michael Halpert Deputy Director Climate Prediction Center Mike.Halpert@noaa.gov http://www.cpc.ncep.noaa.gov Outline About the Seasonal Outlook Review of 2016-17 U. S.

More information

An ENSO-Neutral Winter

An ENSO-Neutral Winter An ENSO-Neutral Winter This issue of the Blue Water Outlook newsletter is devoted towards my thoughts on the long range outlook for winter. You will see that I take a comprehensive approach to this outlook

More information

The Impact of the Extratropical Transition of Typhoon Dale (1996) on the Early Wintertime Stratospheric Circulation

The Impact of the Extratropical Transition of Typhoon Dale (1996) on the Early Wintertime Stratospheric Circulation The Impact of the Extratropical Transition of Typhoon Dale (1996) on the Early 1996-97 Wintertime Stratospheric Circulation Andrea L. Lang 1, Jason M. Cordeira 2, Lance F. Bosart 1 and Daniel Keyser 1

More information

Regional overview Autumn 2016

Regional overview Autumn 2016 Autumn 2016 (March to May inclusive) was drier than average for most of the region. The south and east of the Wairarapa were the driest areas with west coast areas being the wettest. Autumn rainfall The

More information

Tropical Moist Rainforest

Tropical Moist Rainforest Tropical or Lowlatitude Climates: Controlled by equatorial tropical air masses Tropical Moist Rainforest Rainfall is heavy in all months - more than 250 cm. (100 in.). Common temperatures of 27 C (80 F)

More information

Potentially Wet Wed-Fri

Potentially Wet Wed-Fri Potentially Wet Wed-Fri August 18, 2014 Last Week s Lightning Trends TUE 8/12 WED 8/13 THU 8/14 FRI 8/15 t SAT 8/16 SUN 8/17 August 1-16 Precipitation Anomaly: 2013 VS. 2014 AUG 1-16, 2013 AUG 1-16, 2014

More information

La Niña impacts on global seasonal weather anomalies: The OLR perspective. Andrew Chiodi and Ed Harrison

La Niña impacts on global seasonal weather anomalies: The OLR perspective. Andrew Chiodi and Ed Harrison La Niña impacts on global seasonal weather anomalies: The OLR perspective Andrew Chiodi and Ed Harrison Outline Motivation Impacts of the El Nino- Southern Oscillation (ENSO) on seasonal weather anomalies

More information

Atmospheric Circulation

Atmospheric Circulation Atmospheric Circulation Introductory Oceanography Instructor: Ray Rector Atmospheric Circulation Key Topics Composition and Structure Solar Heating and Convection The Coriolis Effect Global Wind Patterns

More information

Weather and Climate Summary and Forecast Summer 2016

Weather and Climate Summary and Forecast Summer 2016 Weather and Climate Summary and Forecast Summer 2016 Gregory V. Jones Southern Oregon University June 6, 2016 May 2016 continued the warm trend for portions of the west, while providing some relief for

More information

JEFF JOHNSON S Winter Weather Outlook

JEFF JOHNSON S Winter Weather Outlook JEFF JOHNSON S 2017-2018 Winter Weather Outlook TABLE OF CONTENTS ABOUT THE AUTHOR Components of the seasonal outlook... 2 ENSO state/ocean temperatures... 3 Sub-seasonal outlooks... 4 Forecast models...

More information

Possible Roles of Atlantic Circulations on the Weakening Indian Monsoon Rainfall ENSO Relationship

Possible Roles of Atlantic Circulations on the Weakening Indian Monsoon Rainfall ENSO Relationship 2376 JOURNAL OF CLIMATE Possible Roles of Atlantic Circulations on the Weakening Indian Monsoon Rainfall ENSO Relationship C.-P. CHANG, PATRICK HARR, AND JIANHUA JU Department of Meteorology, Naval Postgraduate

More information

UPDATE OF REGIONAL WEATHER AND SMOKE HAZE FOR MAY 2015

UPDATE OF REGIONAL WEATHER AND SMOKE HAZE FOR MAY 2015 UPDATE OF REGIONAL WEATHER AND SMOKE HAZE FOR MAY 2015 1. Review of Regional Weather Conditions in April 2015 1.1 Inter-Monsoon conditions prevailed over the ASEAN region in April 2015. The gradual northward

More information

Tokyo Climate Center Website (TCC website) and its products -For monitoring the world climate and ocean-

Tokyo Climate Center Website (TCC website) and its products -For monitoring the world climate and ocean- Tokyo, 14 November 2016, TCC Training Seminar Tokyo Climate Center Website (TCC website) and its products -For monitoring the world climate and ocean- Yasushi MOCHIZUKI Tokyo Climate Center Japan Meteorological

More information

South Asian Climate Outlook Forum (SASCOF-6)

South Asian Climate Outlook Forum (SASCOF-6) Sixth Session of South Asian Climate Outlook Forum (SASCOF-6) Dhaka, Bangladesh, 19-22 April 2015 Consensus Statement Summary Below normal rainfall is most likely during the 2015 southwest monsoon season

More information

Facebook: /nymetrowx Winter Forecast

Facebook: /nymetrowx   Winter Forecast Facebook: /nymetrowx Twitter: @nymetrowx Email: nymetroweather@gmail.com Winter Forecast 2015-2016 Primary Methodologies and Variables of Examination El Nino Southern Oscillation (ENSO) Arctic Oscillation

More information

Chapter 10: Mid-latitude Cyclones Mid-Latitude Cyclones

Chapter 10: Mid-latitude Cyclones Mid-Latitude Cyclones Chapter 10: Mid-latitude Cyclones Mid-Latitude Cyclones Mid-latitude cyclones form along a boundary separating polar air from warmer air to the south. Life Cycle of Cyclone Cyclone Structures Steering

More information

Chapter 10: Mid-latitude Cyclones

Chapter 10: Mid-latitude Cyclones Chapter 10: Mid-latitude Cyclones Life Cycle of Cyclone Cyclone Structures Steering of Cyclone Mid-Latitude Cyclones Mid-latitude cyclones form along a boundary separating polar air from warmer air to

More information

Warm Up Vocabulary Check

Warm Up Vocabulary Check Warm Up Vocabulary Check Surface current Coriolis Effect global winds upwelling Gulf Stream deep current climate El Nino convection current continental deflection 1.The apparent curving of the path of

More information

SEASONAL RAINFALL FORECAST FOR ZIMBABWE. 28 August 2017 THE ZIMBABWE NATIONAL CLIMATE OUTLOOK FORUM

SEASONAL RAINFALL FORECAST FOR ZIMBABWE. 28 August 2017 THE ZIMBABWE NATIONAL CLIMATE OUTLOOK FORUM 2017-18 SEASONAL RAINFALL FORECAST FOR ZIMBABWE METEOROLOGICAL SERVICES DEPARTMENT 28 August 2017 THE ZIMBABWE NATIONAL CLIMATE OUTLOOK FORUM Introduction The Meteorological Services Department of Zimbabwe

More information

Ocean Multi-Decadal Changes and Temperatures By: Joseph D Aleo, CCM

Ocean Multi-Decadal Changes and Temperatures By: Joseph D Aleo, CCM Ocean Multi-Decadal Changes and Temperatures By: Joseph D Aleo, CCM IPCC chapter 3 did a good job explaining the patterns of climate variability through global teleconnections and defining the circulation

More information

SEASONAL CLIMATE PREDICTION

SEASONAL CLIMATE PREDICTION SEASONAL CLIMATE PREDICTION David Walland Australian Bureau of Meteorology WMO RA-V Seminar on Climate Services Honiara, Solomon Islands, 1-4 November 2011 Overview Major climate Drivers in the region

More information

Drought Impacts in the Southern Great Plains. Mark Shafer University of Oklahoma Norman, OK

Drought Impacts in the Southern Great Plains. Mark Shafer University of Oklahoma Norman, OK Drought Impacts in the Southern Great Plains Mark Shafer University of Oklahoma Norman, OK Causes of Drought: Large-Scale, Stationary High Pressure Air rotates clockwise around high pressure steers storms

More information

Northeastern United States Snowstorm of 9 February 2017

Northeastern United States Snowstorm of 9 February 2017 Northeastern United States Snowstorm of 9 February 2017 By Richard H. Grumm and Charles Ross National Weather Service State College, PA 1. Overview A strong shortwave produced a stripe of precipitation

More information

IAP Dynamical Seasonal Prediction System and its applications

IAP Dynamical Seasonal Prediction System and its applications WCRP Workshop on Seasonal Prediction 4-7 June 2007, Barcelona, Spain IAP Dynamical Seasonal Prediction System and its applications Zhaohui LIN Zhou Guangqing Chen Hong Qin Zhengkun Zeng Qingcun Institute

More information

The Atmospheric Circulation

The Atmospheric Circulation The Atmospheric Circulation Vertical structure of the Atmosphere http://www.uwsp.edu/geo/faculty/ritter/geog101/textbook/atmosphere/atmospheric_structure.html The global heat engine [courtesy Kevin Trenberth,

More information

ATOC 5051 INTRODUCTION TO PHYSICAL OCEANOGRAPHY. Lecture 2

ATOC 5051 INTRODUCTION TO PHYSICAL OCEANOGRAPHY. Lecture 2 ATOC 5051 INTRODUCTION TO PHYSICAL OCEANOGRAPHY Lecture 2 Ocean basins and relation to climate Learning objectives: (1)What are the similarities and differences among different ocean basins? (2) How does

More information

Formation of Cold Airmasses Cold Air Outbreak

Formation of Cold Airmasses Cold Air Outbreak Chapter 14: Cold Waves Formation of Cold Airmasses Cold Air Outbreak 1 Cold Wave A cold wave is an influx of unusually cold air into middle or lower latitudes. Cold waves affect much larger areas than

More information

5 Atmospheric Disturbances 7 1.Cyclones- tropical and temperate and associated weather conditions. 2.Anticyclones and associated weather conditions.

5 Atmospheric Disturbances 7 1.Cyclones- tropical and temperate and associated weather conditions. 2.Anticyclones and associated weather conditions. 5 Atmospheric Disturbances 7 1.Cyclones- tropical and temperate and associated weather conditions. 2.Anticyclones and associated weather conditions. atmospheric disturbances (weather systems) that are

More information

SIO 210 Final Exam December 10, :30 2:30 NTV 330 No books, no notes. Calculators can be used.

SIO 210 Final Exam December 10, :30 2:30 NTV 330 No books, no notes. Calculators can be used. SIO 210 Final Exam December 10, 2003 11:30 2:30 NTV 330 No books, no notes. Calculators can be used. There are three sections to the exam: multiple choice, short answer, and long problems. Points are given

More information